Exactly the same works for cabeceo. If I accept myself and do not try to prove anything to anyone, if I unconditionally love myself and know that I'm okay, then I treat the other person similarly. Then we will act without taking something in evil part, and we will give to each other without neurotic desire to be paid back. So when I'm looking at a partner, my 'mirada' (let's call this glance according to tango rules=)) shows a genuine interest, like "hi, I'm glad you're here, let's go dancing, I want to share this beautiful music with you, it'll be fun". I keep this message in my mirada giving the partner right to agree or to refuse. So the partner will not run away or turn away from me. He or she will be calm realizing that the choice to refuse or to accept my invitation will not cause my disappointment or his/her feeling guilty. "No" is not forever, it means that our intentions are not coinciding right here and right now. It's not bad. You just have to take it easy. You know, it's like a child's phrase "Let's play" - "No, I don't want to play now" - "Ah, okay, then later".
By the way, let's discuss women's "responsibility" in tango. We play by men's rules, we strive for equal rights and emancipation, but "they play chess, and we play a giveaway game, and this is our advantage." Dear women, I beg you, be wise. If we assume that men control milonga space and manifest themselves actively, then our influence spreads in an invisible zone.
What do I mean? Here's an example. Let's imagine that you are invited to dance and the partner is so inspired by your "yes" and the music that he tries to break through table-barricades to ronda center. You should stop him (gently and smiling) and offer to enter the ronda from the other place (let it be the corner of the room). Calm the leader down, it's in your interest to do so. Watch the space behind the partner's back, if you dance with your eyes open. Always try to somehow let the nearest dancing couple know that you are going to enter the dancefloor.
Dear gentleman! If you don't ask the couple dancing towards you "permission" to enter ronda, if you try to dive into dancing stream immediately, you act with no respect.
Now almost everyone can drive, so imagine that entering ronda is like entering the circle. You have to give way to those who are already moving in a circle and to those who are going to enter it, too. You do everything carefully avoiding collisions. Just imagine that any "collision" in ronda would lead to calling the "road police" and insurance company, filling relevant documents and so on. Observe simple rules on the dance floor helps us to avoid "traffic jams" and keep the atmosphere positive.
We are not pressed for time, we are already in milonga, the partner has already agreed to dance with you. It's not difficult to wait a few seconds before embracing each other. We are here to enjoy.
Here's a favorite phrase of many dance teachers instead of a summary: "use your head, and you will be happy".